Described herein is a composition and method for the formation of a silicon oxide film. More specifically, described herein is a composition and method for formation of a silicon oxide film at one or more deposition temperatures of about 500° C. or greater and using an atomic layer deposition (ALD) process.
Thermal oxidation is a process commonly used to deposit high purity and highly conformal silicon oxide films such as silicon dioxide (SiO2) in semiconductor applications. However, the thermal oxidation process has a very low deposition rate, e.g., than 0.03 Å/s at 700° C. which makes it impractical for high volume manufacturing processes (see, for example, Wolf, S., “Silicon Processing for the VLSI Era Vol. 1—Process Technology”, Lattice Press, CA, 1986).
Atomic Layer Deposition (ALD) and Plasma Enhanced Atomic Layer Deposition (PEALD) are processes used to deposit silicon dioxide (SiO2) conformal film at low temperature (<500° C.). In both ALD and PEALD processes, the precursor and reactive gas (such as oxygen or ozone) are separately pulsed in certain number of cycles to form a monolayer of silicon dioxide (SiO2) at each cycle. However, silicon dioxide (SiO2) deposited at low temperatures using these processes may contain levels of impurities such as carbon (C), nitrogen (N), or both which are detrimental to semiconductor applications. To remedy this, one possible solution would be to increase deposition temperature such as 500° C. or greater. However, at these higher temperatures, conventional precursors employed by semi-conductor industries tend to self-react, thermally decompose, and deposit in CVD mode rather than ALD mode. The CVD mode deposition has reduced conformality compared to ALD deposition, especially in high aspect ratio structure in semiconductor applications. In addition, the CVD mode deposition has less control of film or material thickness than the ALD mode deposition.
JP2010275602 and JP2010225663 disclose the use of a raw material to form a Si containing thin film such as, silicon oxide by a chemical vapor deposition (CVD) process at a temperature range of from 300-500° C. The raw material is an organic silicon compound, represented by formula: (a)HSi(CH3)(R1)(NR2R3), wherein, R1 represents NR4R5 or a 1C-5C alkyl group; R2 and R4 each represent a 1C-5C alkyl group or hydrogen atom; and R3 and R5 each represent a 1C-5C alkyl group); or (b) HSiCl(NR1R2)(NR3R4), wherein R1 and R3 independently represent an alkyl group having 1 to 4 carbon atoms, or a hydrogen atom; and R2 and R4 independently represent an alkyl group having 1 to 4 carbon atoms. The organic silicon compounds contained H—Si bonds
U.S. Pat. No. 7,084,076 (“the '076 Patent”) discloses a halogenated siloxane such as hexachlorodisiloxane (HCDSO) that is used in conjunction with pyridine as a catalyst for ALD deposition below 500° C. to form silicon dioxide.
U.S. Pat. No. 6,992,019 (“the '019 Patent”) discloses a method for catalyst-assisted atomic layer deposition (ALD) to form a silicon dioxide layer having superior properties on a semiconductor substrate by using a first reactant component consisting of a silicon compound having at least two silicon atoms, or using a tertiary aliphatic amine as the catalyst component, or both in combination, together with related purging methods and sequencing. The precursor used is hexachlorodisilane. The deposition temperature is between 25-150° C.
Thus, there is a need to develop a process for forming a high quality, low impurity, high conformal silicon oxide film using an atomic layer deposition (ALD) process or an ALD-like process, such as without limitation a cyclic chemical vapor deposition process, to replace thermal-based deposition processes. Further, it may be desirable to develop a high temperature deposition (e.g., deposition at one or more temperatures of 500° C.) to improve one or more film properties, such as purity and/or density, in an ALD or ALD-like process.